In the bowl of a stand mixer fitted with a dough hook, combine flour, salt, and baking powder.
Mix briefly to combine.
With the mixer running at medium speed, add oil and water.
Mix for 1-2 minutes, stopping at least once to scrape down the sides of the bowl.
As the dough begins to come together into a ball, reduce mixer speed to low and continue mixing for 1-2 minutes, until dough is smooth.
Transfer dough to a well-floured surface. Divide into 16 balls. Roll and flatten slightly with the palm of your hand. Cover flattened balls of dough with a clean kitchen towel, and allow to rest for at least 15 minutes.
When ready to cook, warm a large cast-iron over medium-high heat.
On a floured surface, roll each dough ball into a circle about 6” in diameter. Do not stack the raw tortillas, as they will stick together.
Transfer tortillas one at a time into the hot skillet. Cook for about 1 minute, until small bubbles form on the top and brown spots form on the bottom surface. Flip and cook the other side for about 30 seconds. Remove from pan and stack cooked tortillas loosely wrapped in a clean kitchen towel.
Serve immediately or allow to cool for later use.
Tortillas can be stored for 2-3 days in the fridge in a plastic zip-top bag.
To make the quesadillas:
Heat 1 teaspoon oil in a medium sauté pan over medium-high heat.
Lay tortilla flat in the pan, and place a chunk of Oaxaca cheese, about 2 (2-inch) long strips, on one tortilla.
Add second tortilla on top.
Cook 3-4 minutes on the first side, carefully flip and cook 1-2 minutes on the second side.
Remove from pan. Slice and sprinkle with green onions.
Serve with guacamole, sour cream, and your favorite salsa.